石杉碱甲对体外培养大鼠脊髓片前角运动神经元损伤的保护作用

目的:利用选择性运动神经元死亡的脊髓薄片培养模型,观察石杉碱甲对运动神经元的保护作用。方法:乳大鼠腰段脊髓组织薄片分为正常对照组、模型组和石杉碱甲1,10,100μmol·L-15组。用倒置显微镜观察脊髓片形态变化,SMI32免疫组化染色对腹角α运动神经元记数,透射电镜观察α运动神经元的超微结构并测定培养液中乳酸脱氢酶(LDH)的含量。结果:石杉碱甲100μmol·L-1组脊髓片在体外生长良好,形态与正常对照组相近;石杉碱甲1,10μmol·L-1组脊髓片生长不良,形态与模型组相近。与正常对照组相比,模型组脊髓片前角SMI32阳性α运动神经元数减少(P<0.05),培养液中LDH含量增加(P<0.05)。与模型组相比,石杉碱甲100μmol·L-1组脊髓片前角α运动神经元数增加(P<0.05),胞浆内空泡明显减少,培养液中LDH含量减低(P<0.05)。结论:高浓度石杉碱甲能改善乳大鼠脊髓片前角α运动神经元生长,减少其空泡形成及死亡,并降低LDH的释放。     

强啡肽A(1-17)在脊髓的致瘫作用及其与神经毒作用的相关性

在以行为学为观察指标(甩尾镇痛和斜板实验)的基础上,用组织学方法探讨大剂量强啡肽A在脊髓水平的致瘫作用与其神经毒作用的关系。结果表明,给大鼠蛛网膜下腔(it)注射强啡肽A(1-17)20nmol·L^-1,共10μl,给药后5～10min即引起大鼠后肢不可逆性瘫痪、甩尾反射被抑制长达40h以上。大鼠脊髓组织学检查发现,腰、骶段脊髓前角运动神经元大量坏死或严重变性、以腰段损伤最为显著(运动神经元减少87.2%),其次是骶段(减少69.6%),胸段损伤不明显(减少8.2%)。     

中华眼镜蛇毒神经生长因子对神经元的保护作用

探讨中华眼镜蛇毒神经在子对受损神经元的保护作用。方法 钳夹损伤成年大鼠坐骨神经,造成脊髓背根神经节感觉神经元和脊髓前角运动神经元变性的动物模型,用酶组织化学图像分析观察神经生长因子对受损神经脊髓节段的抗氟化的酸性磷酸酶和乙酰胆碱酯酶活性的影响。结果 神经生长因子能明显提高受损神经脊髓节段的抗氟化物酸性磷酸酶和乙酰胆碱酯酶活性。结论 神经生长因子对神经元有保护作用。     

缺血后处理增加脊髓miR-125b表达减轻大鼠脊髓缺血-再灌注损伤后神经元凋亡

目的观察缺血后处理(Ischemic postconditioning,IPC)对大鼠脊髓缺血再灌注损伤(Spinal cord ischemia reperfusion injury,SCIRI)后microRNA(miRNA,miR)-125b表达及下肢运动功能的影响。方法 45只SD大鼠平均随机分为3组:假手术组(Sham组)、缺血-再灌注组(IR组)和缺血后处理组(IPC组)。Sham组仅暴露主动脉弓而不夹闭,其他各组夹闭主动脉弓14 min后再开放建立SCIRI模型。IPC组于再灌注5 min后给予5循环缺血后适应。再灌注后24 h,处死大鼠,提取脊髓组织,分别检测脊髓组织湿/干重比(Wet-dry ratio,W/D)和总含水量(Total water content,TWC),HE染色观察脊髓组织病理学变化,qRT-PCR测定脊髓组织中miR-125b表达,TUNEL法检测神经元凋亡数量(Apoptotic quantitiy,AQ)。结果术后24 h,与Sham组比较,IR组大鼠脊髓W/D、TWC、AQ升高,脊髓组织中miR-125b表达下调(P<0.05);与IR组比较,IPC组脊髓W/D、TWC、AQ降低,脊髓组织中miR-125b表达上调(P<0.05)。HE染色显示,Sham组脊髓前角结构完好,可见大量胞核完整的运动神经元,IR组脊髓前角内大量空泡形成,神经元结构缺失,胞质呈嗜酸性,而IPC组脊髓前角存在部分结构正常的神经元。结论缺血后处理可能通过上调脊髓组织中miR-125b的表达,减少脊髓组织前角运动神经元凋亡,从而改善大鼠SCIRI损伤。     

钙敏感受体和钙蛋白酶在大鼠脊髓的表达及其定位

目的 探讨钙敏感受体(CaSR)和钙蛋白酶在大鼠脊髓缺血-再灌注损伤(SCII)中的作用.方法 采用Western blot法检测CaSR在5只健康SD大鼠脊髓中的表达,免疫组化法观察CaSR及钙蛋白酶在脊髓表达的定位.结果 CaSR和钙蛋白酶在大鼠脊髓白质和灰质的前角、侧角及后角均有广泛表达.CaSR在脊髓神经元及神经胶质细胞的胞膜、胞浆和突起部均有表达,而钙蛋白酶仅在神经元的胞浆、胞膜和突起部表达.结论 大鼠脊髓神经元细胞的细胞膜、胞浆及突起部是CaSR和钙蛋白酶的共表达部位,可能参与SCII的发生发展.     

运动训练对脊髓损伤大鼠脊髓内BDNF及其受体TrkB表达的影响

目的 研究运动训练对脊髓损伤（SCI）大鼠脊髓内脑源性神经营养因子（BDNF）及其酪氨酸激酶受体B（TrkB）表达的影响,探讨运动训练促进脊髓损伤功能恢复的可能机制。方法 24只成年雌性SD大鼠随机分为假手术组、损伤对照组和运动训练组。采用通用型脊髓打击器建立大鼠T10脊髓损伤模型。损伤后7天起,对SCI大鼠进行4周运动训练,假手术组和损伤对照组不进行运动训练。损伤前及损伤后第1、2、3、4、5周采用BBB评分评定运动功能。运动训练结束后(即损伤后5周)取大鼠T12～L1节段脊髓,免疫组织化学检测脊髓内BDNF和TrkB表达及分布,Western blot检测脊髓内BDNF和TrkB蛋白含量。结果 运动训练组和损伤对照组BBB评分均较损伤后第1、2周明显提高,运动训练组较损伤对照组增加更为显著（P<0.05）。BDNF免疫反应阳性产物多分布于脊髓前角,脊髓后角及中央管周围也有出现;运动训练组BDNF阳性染色颗粒增多,平均光密度值较假手术组及损伤对照组均显著增加（P<0.05）。TrkB免疫反应阳性产物于脊髓前角、后角、中央管周围等处均出现较多分布;运动训练组TrkB阳性染色颗粒增多,平均光密度值较假手术组及损伤对照组均显著增加（P<0.05）。Western blot结果显示运动训练组大鼠脊髓内BDNF及TrkB的表达较假手术组、损伤对照组均明显增加(P＜0.05)。结论 运动训练能诱导脊髓损伤大鼠脊髓内BDNF及其受体TrkB表达,促进SCI大鼠运动功能恢复。     

碱性成纤维细胞生长因子在大鼠脊髓损伤后的表达及意义

目的:探讨脊髓损伤后的自我保护修复机制.方法:采用改良的Allen’s法建立SD大鼠T11节段脊髓损伤模型,观察术后不同时间段脊髓内碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)蛋白表达分布及变化情况.结果:脊髓损伤各时间段bFGF阳性神经元数较正常组显著增加.7 d达高峰,21 d恢复正常.结论:脊髓损伤后bFGF表达,提示其参与了脊髓损伤后神经元的保护作用.     

靶肌内注射促红细胞生成素对大鼠坐骨神经再生的作用

目的:探讨靶肌内注射人重组促红细胞生成素(recombinant human erythropoietin,rh-EPO)对大鼠坐骨神经损伤后神经再生的作用.方法:选用健康雄性SD大鼠12只,制备大鼠右侧坐骨神经钳夹损伤模型,随机分为2组,每组6只.EPO组:腓肠肌内注射rh-EPO 2 500 U/kg;对照组:腓肠肌内注射等体积的生理盐水.术后第7、14、21 d观察坐骨神经功能指数(SFI),第21 d组织学观察脊髓腰膨大(腰4～6>)、夹伤远端坐骨神经、损伤侧腓肠肌组织并作图像分析,测定脊髓前角运动神经元数、再生有髓神经纤维数、髓鞘厚度、轴突直径和腓肠肌肌细胞横截面积等指标.结果:术后第7 d两组SFI差异无显著性意义,术后第14、21 d EPO组SFI恢复程度明显大于对照组(P<0.05);术后第21 d损伤侧脊髓前角运动神经元数、再生有髓神经纤维数、髓鞘厚度、轴突直径和腓肠肌肌细胞横截面积等指标,EPO组均优于对照组(P<0.05,P<0.01).结论:靶肌内注射rh-EPO能促进周围神经再生和功能恢复.     

靶肌内注射促红细胞生成素对大鼠坐骨神经再生的作用

目的:探讨靶肌内注射人重组促红细胞生成素(recombinant human erythropoietin,rh-EPO)对大鼠坐骨神经损伤后神经再生的作用.方法:选用健康雄性SD大鼠12只,制备大鼠右侧坐骨神经钳夹损伤模型,随机分为2组,每组6只.EPO组:腓肠肌内注射rh-EPO 2 500 U/kg;对照组:腓肠肌内注射等体积的生理盐水.术后第7、14、21 d观察坐骨神经功能指数(SFI),第21 d组织学观察脊髓腰膨大(腰4～6>)、夹伤远端坐骨神经、损伤侧腓肠肌组织并作图像分析,测定脊髓前角运动神经元数、再生有髓神经纤维数、髓鞘厚度、轴突直径和腓肠肌肌细胞横截面积等指标.结果:术后第7 d两组SFI差异无显著性意义,术后第14、21 d EPO组SFI恢复程度明显大于对照组(P<0.05);术后第21 d损伤侧脊髓前角运动神经元数、再生有髓神经纤维数、髓鞘厚度、轴突直径和腓肠肌肌细胞横截面积等指标,EPO组均优于对照组(P<0.05,P<0.01).结论:靶肌内注射rh-EPO能促进周围神经再生和功能恢复.     

肌萎缩侧索硬化症30例临床分析

肌萎缩侧索硬化症(ALS)是运动神经元疾病中最常见的类型,为主要累及脊髓前角细胞、脑干运动神经核及锥体束的神经系统变性疾病,临床表现为上,下运动神经元损害同时并存的特征.     

Localization of mercury in CNS of the rat: III. Oral administration of methylmercuric chloride (CH3HgCl)

The distribution and cellular localization of mercury in the in situ brain and upper cervical spinal cord of adult Wistar rats were studied at various time intervals after oral administration of methylmercuric chloride (CH₃HgCl; 20 mg × liter⁻¹). Coronal sections of the brain and transverse sections of the cervical spinal cord were prepared for visualization of the mercury by the autometallographic silver-enhancement method. Following mercury administration there was a latent period before the metal appeared in the tissue. Mercury staining was first detected after 10 days in cell bodies of five specific areas of the brain stem: the mesencephalic nucleus of the trigeminal nerve, the red nuclei, the ventral cochlear nucleus, the superior vestibular nucleus, and the nucleus reticularis pontis caudalis. After 28 days of treatment, a fairly even distribution of mercury was seen in the brain and spinal cord. Longer periods of treatment caused no further increase in the density of mercury within the stained cell bodies. In cerebral cortex, staining commenced in piriform and entorhinal cortices. This was followed by staining in neurons of lamina III in the isocortex and ultimately all layers were stained after 28 days of treatment. After 20 days of treatment, mercury deposits in the cerebellar cortex were restricted to Purkinje cells, Golgi epithelial cells, and Golgi cells, while in the spinal cord the majority of mercury was located in the anterior horn motoneurons. Scattered ependymal cells and epithelial cells of the choroid plexus also exhibited mercury staining. The principal target cells were neurons followed by the glial and ependymal cells. Ultrastructurally, the bulk of detectable mercury was localized in lysosomes.     

Localization of Mercury in CNS of the Rat III. Oral Administration of Methylmercuric Chloride (CH3HgCl)

The distribution and cellular localization of mercury in thein situ brain and upper cervical spinal cord of adult Wistarrats were studied at various time intervals after oral administrationof methylmercuric chloride (CH₃HgCl; 20 mgxliter^–). Coronalsections of the brain and transverse sections of the cervicalspinal cord were prepared for visualization of the mercury bythe autometallographic silver-enhancement method. Followingmercury administration there was a latent period before themenal appeared in the tissue. Mercury staining was first detectedafter 10 days in cell bodies of five specific areas of the brainstem: the mesencephalic nucleus of the trigeminal nerve, thered nuclei, the ventral cochlear nucleus, the superior vestibularnucleus, and the nucleus reticularis pontis caudalis. After28 days of treatment, a fairly even distribution of mercurywas seen in the brain and spinal cord. Longer periods of treatmentcaused no further increase in the density of mercury withinthe stained cell bodies. In cerebral cortex, staining commencedin piriform and entorhinal cortices. This was followed by stainingin neurons of lamina III in the isocortex and ultimately alllayers were stained after 28 days of treatment. After 20 daysof treatment, mercury deposits in the cerebellar cortex wererestricted to Purkinje cells, Golgi epithelial cells, and Golgicells, while in the spinal cord the majority of mercury waslocated in the anterior horn motoneurons. Scattered ependymalcells and epithelial cells of the choroid plexus also exhibitedmercury staining. The principal target cells were neurons followedby the glial and ependymal cells. Ultrastructurally, the bulkof detectable mercury was localized in lysosomes.     

ATP敏感性钾通道参与兔脊髓缺血预处理的保护作用

目的　探讨ATP敏感性钾通道是否参与兔脊髓缺血预处理的保护作用。方法　 2 7只♂新西兰大白兔随机分成3组 (n =9) :即缺血组 (IC组 )、缺血预处理组 (IPC组 )及格列本脲 (glibenclamide ,ATP敏感性钾通道阻断剂 ) +缺血预处理组 (G +I组 )。IC组夹闭兔腹主动脉肾下段 2 0min ,复制兔脊髓缺血模型 ;IPC组预先使脊髓缺血 6min ,3 0min后再次阻闭兔腹主动脉肾下段 2 0min ;G +I组在缺血预处理前 2 0min静脉给予格列本脲 2mg·kg- 1,其他处理同IPC组。再灌注后 8、12、2 4和 48h分别对动物神经功能评分 ;再灌注 48h后 ,处死动物取脊髓 (L5～ 7) ,制作标本行组织病理学观察。结果　IPC组神经功能评分各时间点均高于IC组及G +I组 (P <0 0 5) ;与IC组及G +I组相比 ,IPC组脊髓前角正常神经细胞数明显增多 (P <0 0 1) ;IC组与G +I组在各时间点的神经功能评分及脊髓前角正常神经细胞数差异都无显著性 (P >0 0 5)。结论　兔脊髓缺血预处理的保护作用与ATP敏感性钾通道密切相关。     

Capsaicin-induced effects on c-fos expression and NADPH-diaphorase activity in the feline spinal cord

The distribution of c-fos expression and NADPH-diaphorase reactivity in the cervical and lumbar segments after stimulation of the vanilloid receptors in the dorsal neck muscles with capsaicin was studied in cats anaesthetized with alpha-chloralose. After the unilateral intramuscular injection of capsaicin, the mean number of Fos-immunoreactive neurons detected with an avidin-biotin-peroxidase technique was significantly increased in the superficial laminae (I), neck of the dorsal horn (V), and area around the central canal (VII) within both the cervical and lumbar spinal cord. Most Fos-immunoreactive neurons in the cervical spinal cord were giant and small cells. The widespread distribution of Fos-immunoreactive cells throughout the cervical cord within the intermediate zone (VII) coincided with the sites of localization of last-order premotor interneurons and cells of origin of inter-segmental crossed and uncrossed descending propriospinal pathways to the lumbar spinal cord. Fos-immunoreactive neurons were co-distributed with nitric oxide-generating cells at both levels of the spinal cord, although the double-labeled cells were not observed. In conclusion, the analysis of c-fos expression and NADPH-diaphorase reactivity shows that stimulation of vanilloid receptors in the neck muscles can initiate distinctive neuronal plasticity in the cervical (C1-C8) and lumbar (L1-L7) segments, and confirms the anatomical and functional coupling of both regions during processing of nociceptive signals from the dorsal neck muscles.     

Lead inclusion bodies in the anterior horn cells and neurons of the substantia nigra in the adult rhesus monkey

The presence of intranuclear lead inclusion bodies was demonstrated in the anterior horn cells of the cervical spinal cord, neurons of the substantia nigra, and renal proximal convoluted tubular cells, in monkeys chronically exposed to lead acetate in their drinking water. This finding in conjunction with damage to the vascular walls and glial processes and ependymal cell degeneration may indicate a possible mechanism for adult lead neuropathy.     

帕罗西汀对糖尿病大鼠神经病理性疼痛的影响及其作用机制

目的 探讨帕罗西汀对糖尿病大鼠神经病理性疼痛的影响及其可能的作用机制。方法 将健康成年♂SD大鼠随机分为3组,每组8只,包括正常对照组、糖尿病组、糖尿病+帕罗西汀治疗组。采用链脲佐菌素（75 mg·kg^-1）一次性腹腔注射建立糖尿病模型,并分别于注射前、注射后7,14,28 d检测机械性缩足反应痛阈（PWMT）。于注射佐脲酶菌素28 d后处理大鼠;取L₄~L₆段脊髓,运用尼氏体染色法检测脊髓组织的形态变化,TUNEL染色检测背角脊髓神经元的凋亡情况,免疫印迹技术检测脊髓神经元血红素加氧酶-1（HO-1）的表达。结果 与正常对照组比较,糖尿病组和糖尿病+帕罗西汀治疗组机械性痛阈明显降低（P<0.05）;与糖尿病组比较,糖尿病+帕罗西汀治疗组大鼠在注射佐脲酶菌素后28 d机械性痛阈显著升高（P<0.05）。糖尿病组大鼠脊髓背角萎缩,神经元变性坏死,细胞数降低,并且尼氏体减少,甚至消失;而糖尿病+帕罗西汀治疗组相对于糖尿病组大鼠脊髓背角萎缩降低,神经元数量升高,可见尼氏体。正常对照组大鼠脊髓背角神经元有较多HO-1表达,而糖尿病组HO-1表达量较低;相对于糖尿病组,糖尿病+帕罗西汀治疗组大鼠脊髓背角神经元有大量HO-1表达。结论 帕罗西汀可以减轻糖尿病大鼠神经病理性疼痛,对脊髓背角神经元具有保护作用,其作用机制可能与上调脊髓背角神经元HO-1的表达有关。     

Activation of group I metabotropic glutamate receptors induces long-term depression at sensory synapses in superficial spinal dorsal horn

Low-frequency stimulation of primary afferent Adelta-fibers can induce long-term depression of synaptic transmission in rat superficial spinal dorsal horn. Here, we have identified another form of long-term depression in superficial spinal dorsal horn neurons that is induced by specific group I but not group II metabotropic glutamate receptor (mGluR) agonists. Synaptic strength between Adelta-fibers and dorsal horn neurons was examined by intracellular recordings in a spinal cord-dorsal root slice preparation from young rat. In the presence of bicuculline and strychnine, bath application of (1S,3R)-1-aminocyclopentane-1, 3-dicarboxylic acid ((1S,3R)-ACPD) or the specific group I mGluR agonist (S)-3,5-dihydroxyphenylglycine ((S)-3,5-DHPG) but not the specific group II mGluR agonist (2S,2'R,3'R)-2-(2', 3'-dicarboxycyclopropyl)glycine (DCG-IV) for 20 min produced an acute and a long-term depression of synaptic strength. Bath application of the N-methyl-D-aspartate receptor antagonist D-2-amino-5-phosphonovaleric acid did not affect these depressions by (1S,3R)-ACPD. After pre-incubation of slices with pertussis toxin, a G-protein inhibitor, (1S,3R)-ACPD still induced acute and long-term depressions. The phospholipase C inhibitor U73122 stereoselectively blocked the induction of long-term depression without affecting acute synaptic inhibition. This study demonstrates that, in the spinal cord, direct activation of group I mGluRs that are coupled to phospholipase C through pertussis toxin-insensitive G-proteins induces a long-term depression of synaptic strength. This may be relevant to the processing of sensory information in the spinal cord, including nociception.     

颈前路手术治疗脊髓型颈椎病并颈椎外伤所致急性颈髓损伤19例临床分析

目的探讨颈前路椎体次全切并后纵韧带切除减压植骨融合术治疗脊髓型颈椎病并颈椎外伤所导致的急性颈髓损伤的疗效。方法回顾性分析采用颈前路椎体次全切并后纵韧带切除减压植骨融合术治疗的脊髓型颈椎病并颈椎外伤所导致的急性颈髓损伤的19例患者病历资料,对患者外伤前（T1）、外伤后（T2）、术后1周内几）、术后10个月后几）四个时期的颈椎曲度及神经功能评分（JOA）变化进行分析,判断手术疗效。结果所有患者均获得10—24个月随访,平均（15．2±6．7）个月。T1、T2、T3、T4四个时期的颈椎曲度分别为（28．621±1．850）°、（29．326±2．416）°、（38．384±2．611）°、（37．316±2．521）°。T1、T2、T3、T4四个时期的JOA脊髓型颈椎病评分分别为（12．79±1．316）、（4．00±2．082）、（9．68±3．001）、（11．68±3．334）。结论颈前路椎体次全切并后纵韧带切除减压植骨融合术可达到有效减压效果、可重建颈椎曲度,能提供脊髓型颈椎病并颈椎外伤所导致的颈髓损伤有效康复条件;术后积极康复治疗也是改善神经功能的重要方法。